Air pre cleaner

ABSTRACT

An air pre-cleaner mounted on the air intake pipe of an internal combustion engine and connected to an exhaust aspirator mounted on the engine exhaust pipe. The pre-cleaner has a cylindrical housing having an air inlet for circumferentially directing air and foreign materials to a separation chamber. A plate baffle having a peripheral edge portion spaced from the inside wall of the housing separates a low pressure chamber from the separation chamber. A clean air exit passage, coupled with the air intake pipe of the engine, opens into the center of the separation chamber. The aspirator withdraws air from the low pressure chambers over the top of the baffle whereby air is continuously moved through the housing in a circumferential direction separating foreign materials from the air moving into the air intake pipe of the internal combustion engine.

United States Patent [191 Borsheim June 26, 1973 [73] Assignee: Ross K.Petersen, Minneapolis,

Minn.

22 Filed: May 10,1971

211 Appl.No.: 141,758

[52] US. Cl 55/394, 55/426, 55/431, 55/457, 55/DIG. 28 [51] Int. Cl B0ld45/12 [58] Field of Search 55/DIG. 28, 392-399, 55/424, 426, 428-431,456-457 [56] References Cited UNITED STATES PATENTS 1,434,562 11/1922Quam 55/D1G. 28

1,530,645 3/1925 Brockway 55/DlG. 28 1,539,797 5/1925 Chandler et al.55/DIG. 28 1,743,522 1/1930 Bull 55/398 X 1,853,838 4/1932 White 55/DIG.28 1,864,201 6/1932 Kegerreis et a1 55/DIG. 28 1,934,311 11/1933Kegerreis et a1 55/394 2,193,479 3/1940 Donaldson 55/429 3,137,553Billey 55/DlG, 28

11/1967 Wilson 55/337 6/1972 Petersen 55/DIG. 28

Primary Examiner-Frank W. Lutter Assistant Examiner-Vincent GiffordAttorney-Burd, Braddock & Bartz [5 7] ABSTRACT An air pre-cleanermounted on the air intake pipe of an internal combustion engine andconnected to an exhaust aspirator mounted on the engine exhaust pipe.The pre-cleaner has a cylindrical housing having an air inlet forcircumferentially directing air and foreign materials to a separationchamber. A plate baffle having a peripheral edge portion spaced from theinside wall of the housing separates a low pressure chamber from theseparation chamber. A clean air exit passage, coupled with the airintake pipe of the engine, opens into the center of the separationchamber. The aspirator withdraws air from the low pressure chambers overthe top of the baffle whereby air is continuously moved through thehousing in a circumferential direction separating foreign materials fromthe air moving into the air intake pipe of the internal combustionengine.

12 Claims, 6 Drawing Figures PATENIEDJUIIZB I873 SHEEIIBFZ INVENTOR.LEWIS A. BORSHEIM Judd,

AT TORNEYS PATENIEUJUIZB I973 SIEEIZUZ INVENTOR. LEWIS A. BORSHEIMATTORNEYS AIR PRE-CLEANER BACKGROUND OF INVENTION Air pre-cleaners areused on the inlets of air cleaners to prevent coarse or fuzzy solidmaterial, as dirt, chaff, snow, lint and other particulate material fromentering the air cleaner. If this material is allowed to enter the aircleaner or'the carburetor, it will impair the performance of the engine.An air pre-cleaner on the inlet to an air cleaner will reduce thefrequency of service of the air cleaner where extreme dust and dirtconditions are encountered. The pre-cleaner is used to separate themajority of the dust and foreign materials from the incoming air streamthereby increasing the effective dust collection capacity of the aircleaner.

Air cleaners of the centrifugal type have air deflecting structureswhich provide the air with a spiral motion to separate the dust carriedin the air. The cleaned air is drawn into the inlet of an engine.Examples of this structure are shown in U.S. Pat., No. 1,501,144, U.S.Pat. No. 1,743,521 and U.S. Pat. No. 1,906,432. The use of the exhaustto provide a flow of air through a pre-cleaner is shown in U.S. Pat. No.1,539,797, U.S. Pat. No. 3,137,553 and U.S. Pat. No. 3,354,621.

SUMMARY OF INVENTION The invention relates to a device for separatingforeign particulate materials from fluid, as air, carrying theparticulate materials. The device is an air precleaner having a housingdivided into a separation chamber or compartment and a low pressurechamber or compartment with a baffle located within the housing. Thebaffle has an outer peripheral edge portion spaced from the inside wallof the housing forming a restricted throat. The low pressure chamberabove the baffle is connected to a means for withdrawing air and foreignmaterials from the low pressure chamber so that fluid and foreignmaterials flow through both chambers. As the fluid flows through theseparation chamber, it is directed in a circumferential or spiraldirection whereby centrifugal force separates the foreign material fromthe air in the central portion of the separation chamber. The cleanedair flows into an air outlet as the inlet pipe to an internal combustionengine. The air containing the foreign material flows through the throatto the low pressure chamber and out to the means for withdrawing the airfrom the low pressure chamber. 1

More specifically, the housing has a continuous upright cylindricalinside wall adjacent both the separation chamber and the low pressurechamber. The fluid inlet passage means is on the bottom of theseparation chamber and directs the fluid in a circular and upwarddirection into the separation chamber. This circular and upwarddirection is maintained as the fluid flows through the restricted throatbetween the baffle means and the housing into the low pressure chamber.The restricted throat reduces the pressure in the low pressure chamberand increases the velocity of the fluid moving toward and through thethroat. This increases the separating effectiveness of the device. Thesecond outlet opening is tangentially open to the low pressure chamberand thus aids in maintaining the centrifugal motion of the fluid. Theclean air is extracted from the separation chamber through an opening inthe central section of the separation chamber. The opening is centrallyaligned to capture the inner vortex of the clean air formed in thiscyclone separator. The tangential exit opening does not create a changein the circular or circumferential movement of the air and entrainedparticles. This provides for a maximum pressure drop and the greatestseparating efficiency of the entrained particles from the air.

IN THE DRAWINGS FIG. 1 is a fragmentary elevational view of a tractorequipped with the air pre-cleaner of the invention;

FIG. 2 is an enlarged sectional view of the air precleaner shown in FIG.1;

FIG. 3 is a fragmentary top plan view, partly sectioned, of the airpre-cleaner of FIG. 2;

FIG. 4 is a sectional view taken along the line 4-4 of FIG. 2;

FIG. 5 is a sectional top view taken along line 5-5 of FIG. 6 of amodification of the air pre-cleaner of the invention; and

FIG. 6 is a sectional view taken along the line 5-5 of FIG. 5.

Referring to the drawings, there is shown in FIG. 1 an air cleaneraccessory or air pre-cleaner, indicated generally at 10, operativelyassembled on a tractor 11 to remove a substantial portion of the foreignmaterials from the air flowing to the air cleaner connected to thecarburetor of the internal combustion engine of the tractor. Tractor 11has an air intake pipe 12 and an exhaust muffler 13 having a shortexhaust pipe 14. The air pre-cleaner 10, mounted on the inlet end of theintake pipe 12, is connected with a flexible tube or rubber hose 16 toan exhaust aspirator, indicated generally at 17, mounted on the exhaustpipe 14. Exhaust aspirator 17 functions as a suction means tocontinuously withdraw air and foreign materials through the airprecleaner in a manner that separates the foreign materials from the airthat flows through the air pre-cleaner into the intake pipe 12. Theaspirator 17 can be mounted on the exhaust structure of any internalcombustion engine to provide a suction means to continuously withdrawfluid and foreign particles from the pre-cleaner.

Referring to FIG. 2, air pre-cleaner 10 has a generally circularhousing, indicated generally at 18, comprising a top wall 19 adjoined toa cylindrical side wall 21. The side wall 21 has a smooth uprightcylindrical inside surface 22 of a uniform diameter. Located withinhousing 18 is a baffle 23 comprising a plate having a forward continuousperipheral edge 24 spaced a uniform distance from a portion of theinside surface 22 to form an uninterrupted throat or space 26. The edge24 terminates into a downwardly directed lip 27 that extends to theinside surface 22. The plate then follows the cylindrical surface to thetop wall 19. The plate, as shown in FIG. 3, follows a generally chordalline along the top wall to the upper edge of the leading peripheral edge24. The baffle 23 separates the space within the housing 18 into aseparation chamber 28 and a low pressure chamber 29. The low pressurechamber 29 is located generally adjacent the upper part of and to oneside of the separation chamber 28. The low pressure chamber 29 is abovethe baffle 23.

Secured to the housing side wall adjacent the low pressure chamber 29 isa fluid exit tube 31 having a passageway 32. The passageway 32 follows atangential line with respect to the cylindrical inside surface wherebyair and particles leaving the low pressure chamber 29 follow atangential path.

The housing 18 is mounted on a base indicated generally at 33. Base 33has a generally upright cylindrical sleeve 34 attached to the side wall21 with a plurality of fasteners 36, as screws, bolts or the like.Located concentrically within the sleeve 34 is a cylindrical centralmember 37 adjoined to the inlet pipe 12. The cylindrical member 37 has atop mouth 38 surrounded by an outwardly directed annular lip 39. Themouth leads to an axial passageway 41 to direct the clean air into theintake pipe 12. The cylindrical member 37 is attached to the sleeve 34with a plurality of circumferentially disposed and upwardly inclinedvanes or blades 42. Adjacent vanes 42 are spaced from each other toprovide spiral passageways or inlet openings. Each vane 42 has a bottomedge located closely adjacent the bottom edge of the member 37 and a topedge located along the top of the member 37. Portions of adjacent vanesare spaced in overlapping positions to prevent axial flow of air throughthe base 33. The sides of the vanes 42 are secured by rivets, bolts,welds or the like to the sleeve 34 and member 37. The housing 18, baffle23 and base 33 can be made of metal, plastic or like materials.

On operation of the internal combustion engine, the exhaust gases andair flow through the aspirator 17 which causes a suction or vacuum forcein the low pressure chamber 29. The reduction in pressure chamber 29causes the air to move upwardly in the separation chamber 28 carryingwith it the foreign materials in the air, as dust, dirt, snow and otherparticulate materials. The inlet openings between the vanes 42 initiallydirect the air entering the separation chamber'28 in a spiral orcircumferential pattern as indicated by arrows 43. This circular motionof the air causes a centrifugal separation of the particles of foreignmaterial from the air, moving these particles outwardly toward theinside surface 22. The air in the center area of the chamber 28 is drawnor sucked downwardly through the passageway 41 to the air cleaner and/orcarburetor of the engine. The relatively clean air in the center portionof the separation chamber 28 is removed through the member 37 which isopen to the lower portion of chamber 28. Passageway 41 is centrallyaligned to capture the inner vortex of the clean air formed by thiscyclone separator.

The second or fluid outlet passageway 32 is generally tangent with andopen to the low pressure chamber 29. The tangential exit passageway 32does not require a change in the circular motion of the air andentrained particles to be removed from the chamber 29. Since there is nochange in the direction of movement of the flowing air and particles,they do not separate or inhibit particulate flow. Also, the continuouscentrifugal action on the particles holds the particles entrained in theair, which provides for a maximum pressure drop between the separationchamber 28 and the low pressure chamber 29. The leading edge 24 of thebaffle 23 is a continuous configuration and is uniformly spaced from theinside surface 22 to provide an uninterrupted restricted throat betweenthe separation chamber 28 and the low pressure chamber 29. The airmoving through the throat increases in velocity and will have greatercarryinG capacity of particulate material.

Referring to FIGS. and 6, there is shown a modification of the airpre-cleaner of the invention, indicated generally at 100. Thepre-cleaner 100 is adapted to be operatively assembled on an air intakemember of an internal combustion engine, as a tractor, to remove foreignmaterials from the air flowing to the carburetor or conventional aircleaner connected to the carburetor. Pre-cleaner has a one-pieceinverted cup-shaped housing 101. The housing 101 has a cylindricalupright side wall 102 integrally joined to a flat top wall 103. Theinside of wall 102 has a smooth cylindrical surface 102A. Positionedaxially within the lower portion of the side wall 102 is an uprightcylindrical member or sleeve 104 having an upright passageway 105 opento the inside of the housing. A plurality of spaced inclined vanes orblades 106 attach the sleeve 104 to the housing side wall 102. The upperportion or inlet mouth 107 of the sleeve 104 has an outwardly directedflare which func tions to divert incoming air and foreign materialsoutwardly toward the side wall 102. The lower end of sleeve 104 hascircumferentially spaced upright slots 108 which permit the sleeve to beclamped about an air inlet pipe (not shown) leading to the carburetor ofan internal combustion engine. A conventional circular clamp 109,positioned about the lower end of the sleeve 104, is operative to fastenthe sleeve to the pipe. The entire housing may be made of metal, plasticor like materials.

The vanes 106 are positioned in an overlapped spiral location relativeto each other to form upwardly inclined inlet openings 111 betweenadjacent vanes. The upper edges of each vane 106 are located above thetop of the sleeve 104 so that the incoming air and foreign material isdirected in a circumferential manner into an unobstructed separationchamber 113. The upper portion of the vanes 106 also are inclinedupwardly and outwardly so that the heavier foreign materials are carriedoutwardly adjacent the inside surface of the side wall 102. Thiscircular action establishes centrifugal forces that carry the heavyforeign particles, as dirt, dust and other particulate matter, outwardlyand upwardly toward the top of the housing 101, as shown by arrows 112in FIG. 5.

Positioned across the top of the separation chamber 113 is a flat baffle116 comprising a circular plate or disc having an annular uninterruptedperipheral edge portion 117. The annular peripheral edge portion 117 ofthe disc is spaced a short distance from the side wall 102 providing anannular restriction 118 between the separation chamber'll3 and a lowpressure chamber 121. A circular ring or support 119, secured to thebottom of the top wall 103,carries the plate 116 and reduces the size ofthe low pressure chamber. The top of the plate 116 is secured to thebottom of the ring 119. The peripheral portion 117 of the disc ismaintained a short distance, approximately 1$ of an inch, from theinside of the side wall 102.

As shown in FIG. 6, the ring 119 is axially offset with respect to thesleeve 104 and the center of the top wall 103. The low pressure chamber121 has a large portion, indicated at A, on one side of the ring 119 anda small portion, indicated at B, on the opposite side of the ring.Secured to the upper portion of the side wall 102 is a tangentiallydirected outlet tube 122 having a tangential passageway 123 open to thelarge portion A of the low pressure chamber. The outlet tube 122 isadapted to be connected to the aspirator so that air and foreignmaterials, as indicated by arrow 124, are pulled from the large portionof the low pressure chamber 121. The positioning of the outlet tube 122in a tangential direction and opening the passageway 123 to the largeportion A of the low pressure chamber is instrumental in maintaining thecircular motion of the air and foreign materials so that there is aminimum of settling of the foreign materials in the low pressure chamber121. In addition, this structure creates a more effective low pressurecondition, thereby increasing the suction action of the air as it movesthrough the annular restricted throat 1 18.

In use, the exhaust gases and air flowing through the exhaust aspiratormounted on an internal combustion engine create a suction force whichwithdraws air and foreign materials from the low pressure chamber 121.The reduction of pressure in chamber 121 causes air to move upwardlythrough the separation chamber 113. This moving air carries with itforeign materials that are in the air, as dust, dirt, snow and otherparticulate materials. As the outside air moves through the inletopenings 111, it is directed in a circumferential or spiral directioninto the unobstructed separation chamber 113. This movement of the aircauses centrifugal separation of the heavier foreign materials from theair in the center portion of the separation chamber. The clean air inthe center of the separation chamber is drawn down into sleeve 104toward the carburetor. The foreign materials move upwardly along thesmooth inside surface of the side walls 102. As they approach theannular restricted opening or throat 118, there is a large suction forcecaused by a sharp reduction in pressure, on venturi action, which pullsthe foreign materials and air into the low pressure chamber 121. The airmoving from the large area A of the low pressure chamber continues thecircular motion of foreign particles that are tangentially expelledthrough the passageway 123 into the exhaust aspirator.

ln summary, the device is operable to separate foreign particulatematerials from fluids, as air, water and the like, by concentrating theparticulate materials in a portion of the fluid by using sharp reductionin pressure and centrifugal forces established by spirally moving thefluids. The fluids carrying the materials move outwardly to a restrictedthroat. The sharp reduction in pressure increases the velocity of thefluids whereby the particulate materials are carried through the throatto an exit passage.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows: v

1. A device for separating foreign particulate materials from a fluidcomprising: housing means having a continuous upright cylindrical insidesurface surrounding a cylindrical separation chamber and a low pressurechamber located generally adjacent the upper portion of the separationchamber; a first means having fluid inlet passage means open to thebottom of said separation chamber for directing fluid in a circular andupward direction into the separation chamber; sleeve means having afirst fluid outlet means open to the central section of the separationchamber; a second means having a second fluid outlet passage generallytangentially open to the low pressure chamber; baffle means located insaid housing means separating the separation chamber from the lowpressure chamber, said baffle means having a continuous outer peripheraledge portion, the entire peripheral edge portion being spaced inwardfrom the inside wall of the housing means to connect the separationchamber with the low pressure chamber with an uninterrupted restrictedthroat, said baffle means extends downwardly and inwardly toward theinside wall of the housing means, said throat extends downwardly alongthe inside wall of the housing means, said second fluid outlet passageconnectable to suction means to continuously withdraw fluid and foreignparticulate materials from the low pressure chamber wherby particulatematerials in the fluid flowing through the fluid inlet passage means areseparated from the fluid moving to the first fluid outlet means in theseparation chamber, said particulate materials moving circumferentiallyand upwardly along the inside surface of the housing means through therestricted throat into the low pressure chamber and tangentially out ofthe housing means through the second fluid outlet passage.

2. The device of claim 1 wherein: said baffle means is a plate memberlocated in said housing means to separate the separation chamber fromthe low pressure chamber, said outer peripheral edge portion of thebaffle means being the forward edge of the plate member, said edgespaced from and extended downwardly adjacent said inside surface of thehousing.

3. The device of claim 1 wherein: the outer peripheral edge portion ofthe baffle means is uniformly spaced from the inside wall of the housingmeans whereby the throat has a generally uniform width. I

4. The device of claim 1 wherein: said housing means has a plurality ofspaced circumferentially extended vanes located only in the first inletmeans to direct the incoming fluid in a circumferential direction aroundthe separation chamber.

5. The device of claim 1 wherein: said housing means has a base, saidbase having said sleeve means with a passageway comprising the firstfluid outlet means and a plurality of spaced circumferentially extendedoverlapped vanes located only in the first fluid inlet means to directthe incoming fluid in a circumferential direction around the separationchamber.

6. The device of claim 1 wherein: the low pressure chamber issubstantially smaller than the separation chamber.

7. A device for separating foreign particulate materials from a fluidcomprising: housing means having a continuous upright cylindrical insidesurface surrounding a cylindrical separation chamber and a low pressurechamber located generally adjacent the upper portion of the separationchamber; a first means having fluid inlet passage means open to thebottom of said separation chamber for directing fluid in a circulardirection and upward direction into the separtion chamber; sleeve meanshaving a first fluid outlet means open to the central section of theseparation chamber; second means having a second fluid outlet passagegenerally tangentially open to the low pressure chamber; baffle meanslocated in said housing means separating the separation chamber from thelow pressure chamber, said baffle means having a continuous outerperipheral edge portion, the entire peripheral edge portion being spacedinwardly from the inside wall of the housing means to connect theseparation chamber with the low pressure chamber with an uninterruptedrestricted throat, said baffle means being a plate member located insaid housing means to separate the separation chamber from the lowpressure chamber, said outer peripheral edge portion of the baffle meansbeing the forward edge of the plate member, said edge being spaced frommeans has a base, said base having sleeve means with a passagewaycomprising the first fluid outlet means and a plurality of spacedcircumferentially extended overlapped vanes located only in the firstfluid inlet means to direct the incoming fluid in a circumferentialdirection around the separation chamber.

12. The device of claim 7 wherein: said housing means has a plurality ofspaced circumferentially extended vanes located only in the first fluidinlet means to direct the incoming fluid in a circumferential directionaround the separation chamber.

1. A device for separating foreign particulate materials from a fluidcomprising: housing means having a continuous upright cylindrical insidesurface surrounding a cylindrical separation chamber and a low pressurechamber located generally adjacent the upper portion of the separationchamber; a first means having fluid inlet passage means open to thebottom of said separation chamber for directing fluid in a circular andupward direction into the separation chamber; sleeve means having afirst fluid outlet means open to the central section of the separationchamber; a second means having a second fluid outlet passage generallytangentially open to the low pressure chamber; baffle means located insaid housing means separating the separation chamber from the lowpressure chamber, said baffle means having a continuous outer peripheraledge portion, the entire peripheral edge portion being spaced inwardfrom the inside wall of the housing means to connect the separationchamber with the low pressure chamber with an uninterrupted restrictedthroat, said baffle means extends downwardly and inwardly toward theinside wall of the housing means, said throat extends downwardly alongthe inside wall of the housing means, said second fluid outlet passageconnectable to suction means to continuously withdraw fluid and foreignparticulate materials from the low pressure chamber wherby particulatematerials in the fluid flowing through the fluid inlet passage means areseparated from the fluid moving to the first fluid outlet means in theseparation chamber, said particulate materials moving circumferentiallyand upwardly along the inside surface of the housing means through therestricted throat into the low pressure chamber and tangentially out ofthe housing means through the second fluid outlet passage.
 2. The deviceof claim 1 wherein: said baffle means is a plate member located in saidhousing means to separate the separation chamber from the low pressurechamber, said outer periPheral edge portion of the baffle means beingthe forward edge of the plate member, said edge spaced from and extendeddownwardly adjacent said inside surface of the housing.
 3. The device ofclaim 1 wherein: the outer peripheral edge portion of the baffle meansis uniformly spaced from the inside wall of the housing means wherebythe throat has a generally uniform width.
 4. The device of claim 1wherein: said housing means has a plurality of spaced circumferentiallyextended vanes located only in the first inlet means to direct theincoming fluid in a circumferential direction around the separationchamber.
 5. The device of claim 1 wherein: said housing means has abase, said base having said sleeve means with a passageway comprisingthe first fluid outlet means and a plurality of spaced circumferentiallyextended overlapped vanes located only in the first fluid inlet means todirect the incoming fluid in a circumferential direction around theseparation chamber.
 6. The device of claim 1 wherein: the low pressurechamber is substantially smaller than the separation chamber.
 7. Adevice for separating foreign particulate materials from a fluidcomprising: housing means having a continuous upright cylindrical insidesurface surrounding a cylindrical separation chamber and a low pressurechamber located generally adjacent the upper portion of the separationchamber; a first means having fluid inlet passage means open to thebottom of said separation chamber for directing fluid in a circulardirection and upward direction into the separtion chamber; sleeve meanshaving a first fluid outlet means open to the central section of theseparation chamber; second means having a second fluid outlet passagegenerally tangentially open to the low pressure chamber; baffle meanslocated in said housing means separating the separation chamber from thelow pressure chamber, said baffle means having a continuous outerperipheral edge portion, the entire peripheral edge portion being spacedinwardly from the inside wall of the housing means to connect theseparation chamber with the low pressure chamber with an uninterruptedrestricted throat, said baffle means being a plate member located insaid housing means to separate the separation chamber from the lowpressure chamber, said outer peripheral edge portion of the baffle meansbeing the forward edge of the plate member, said edge being spaced fromand extended downwardly adjacent the inside surface of the housingmeans.
 8. The device of claim 7 wherein: the baffle means is a generallyflat plate member.
 9. The device of claim 7 wherein: said edge portionof the baffle means is uniformly spaced from the inside surface of thehousing whereby said throat has a generally uniform width.
 10. Thedevice of claim 7 wherein: the low pressure chamber is substantiallysmaller than the separation chamber.
 11. The device of claim 7 wherein:said housing means has a base, said base having sleeve means with apassageway comprising the first fluid outlet means and a plurality ofspaced circumferentially extended overlapped vanes located only in thefirst fluid inlet means to direct the incoming fluid in acircumferential direction around the separation chamber.
 12. The deviceof claim 7 wherein: said housing means has a plurality of spacedcircumferentially extended vanes located only in the first fluid inletmeans to direct the incoming fluid in a circumferential direction aroundthe separation chamber.